Internal combustion engines have been utilized since their advent for myriad applications, particularly to generate power (such as, as one example, electricity) through the combustion of certain fuels. The ability to ignite combustible materials within an enclosed system allows for transfer of such energy to a proper power transfer device (such as a dynamo, for instance) in order to allow for electricity supplies at remote or mobile locations. Such devices thus include a suitable air intake component to properly combine oxygen within the combustion chamber for proper ignition.
Although many internal combustion engines are utilized in relatively “safe” locations (such as within automobiles or at construction sites), other locations have proven rather risky for the presence and utilization of such devices due to the delicate nature of the site or the environmental conditions themselves. For instance, mining operations require electricity (and possibly other sources of power generation) but may be subject to potentially hazardous environmental conditions if flammable gases or other explosive compounds are released in the vicinity of such an engine. As another example, oil rigs require a great amount of electricity (or other power sources) to run the drilling machines and other mechanical devices, but any explosive potential may cause very dangerous results. The improper running or undesired introduction of flammable fuels upon shutdown within an internal combustion engine could have terrible consequences in such a delicate environment. There are certainly many other instances of such hazardous possibilities with internal combustion engines present, as well.
As a result, certification of such combustion equipment is required for such types of locations. In particular, in areas where a potential release of flammable gas or vapor may occur, industrial standards have been set to concern the level of risk for exposure to such conditions. For example, such hazardous environment applications may be categorized as Group I Division 2, a label set within the National Electrical Code (NEC) Article 500.5 (B)(2) as a location in which flammable gases or vapors are normally confined within enclosed containers or closed systems from which they can escape only in case of accidental breakdown of processes or equipment. Such a definition is rather easily met by a engine including totally mechanical parts as no sparks or combustible fuels would cause such problems. However, with electrical systems, such a standard provides a heightened degree of caution in order to best limit further destructive consequences through such a potential introduction of hazardous flammable liquids within such an electrically controlled combustion chamber. The provision of an appropriately protective and presumably flammable liquid preventive electricity generating internal combustion engine is thus required by regulatory agencies.
In essence, then, past hazardous environment applications required, at a minimum, a redundant engine shutdown system (as well as a primary standard engine shutdown system) in order to thwart any appreciable potential for flammable liquid or vapor introduction within such an internal combustion engine during standard use. Past redundant engine shutdown systems have been rather limited in their overall capability, however, particularly due to the general potential for monitoring for certain excessive or low readings through internal sensors. If such measurements meet certain parameters, then the shutdown system becomes activated, effectively turning off the overall device. Such a shutdown, however, does not control the combustion chamber itself, and merely allows for the shutdown of power to the overall engine. The continued combustion chamber operation (in one such instance, at least) may still lead to undesirable flammable liquid introduction therein, thus compromising, potentially, not only the usefulness of the subject internal combustion engine in total, but the safety of the entire surrounding area as the hazardous environment requirements, noted above, would be breached if the combustion chamber itself remained in operable and running condition. Serious, if not total, damage to the subject engine or surrounding devices, machines, and/or instruments, may thus occur subsequent to actual engine shutdown. Avoiding such consequential and potentially significant problems, both technically and financially, is thus of great importance to the industry.
The pertinent prior art does provide certain systems for possible engine shutdown, but with limited utility in terms of sensor usage and correlated shutdown potential. There is no teaching nor fair suggestion within the pertinent industrial area of an engine that utilizes not only a multi-operable sensor system, but also provides explosion protection to an externally located control panel, as well as a manual override in case the situation and/or environment dictates operator involvement. The limited redundant shutdown systems in the prior art (such as within U.S. Pat. No. 7,072,761 to Hawkins et al.) fail to take into account the further necessities of air intake shutdown valve usage, nor the removal of a control box from the surface of the subject internal combustion engine itself.
Without any such protections in place, it is difficult to fathom the possible utilization of such engines in Class I locations without first being subject to high scrutiny by a private regulatory compliance organization (such as Underwriters Laboratories, for instance). Thus, the ability to undertake a properly designed internal combustion engine system within such a designated hazardous location with reliable components to compensate for any and all potential safety breaches that fall within the Class I Division II category would be of great importance. Unfortunately, to date, there have been no such internal combustion engine devices that meet such stringent requirements, particularly including all of the above-described components. Although some devices have been provided commercially that incorporate individual components (such as an intake shutoff, or perhaps an auxiliary spark preventing muffler), no devices including multiple protective measures of these types have yet to be accorded the power generation industry, specifically in terms of developing an engine that meets certain rigid standards for, as one example, Underwriter Laboratories acceptance for certain potentially hazardous locations.